Remove user avatars from the admin user table

remove-avatar-user-table.php

<?php
add_filter( 'pre_get_avatar', 'rkv_remove_avatar_from_list', 10, 3 );
/**
 * Remove the avatars from just the admin user list table.
 *
 * @param string $avatar       HTML for the user's avatar. Default null.
 * @param mixed  $id_or_email  The Gravatar to retrieve. Accepts a user_id, gravatar md5 hash,
 *                             user email, WP_User object, WP_Post object, or WP_Comment object.
 * @param array  $args         Arguments passed to get_avatar_url(), after processing.
 *
 * @return string              An empty string.
 */
function rkv_remove_avatar_from_list( $avatar, $id_or_email, $args ) {

    // Do our normal thing on non-admin or our screen function is missing.
    if ( ! is_admin() || ! function_exists( 'get_current_screen' ) ) {
        return $avatar;
    }

    // Get my current screen.
    $screen = get_current_screen();

    // Bail without the object.
    if ( empty( $screen ) || ! is_object( $screen ) || empty( $screen->base ) || 'users' !== $screen->base ) {
        return $avatar;
    }

    // Return an empty string.
    return '';
}